Driving apparatus

Abstract

To realize a driving apparatus where vibrational movement of a piezoelectric element is ensured; sufficient impact resistance is provided; and damages to the piezoelectric element is prevented, a driving apparatus of the present invention has: a flex movement member 1 A or 1 B for serving as a driving source to drive a lens barrel 4 , the flex movement member including: a piezoelectric member 22 X or 22 Y which extends and contracts under electric control; and a shim 21 larger than the piezoelectric member 22 X or 22 Y, the piezoelectric member and the vibrational plate attached to each other; and protruding sections 8 for restricting an excessive flex movement of the shim 21 of the flex movement member 1 A or 1 B, the protruding sections 8 being at a position where the protruding sections 8 will not contact with the piezoelectric member 1 A or 1 B of the flex movement member 22 X or 22 Y when the flex movement member is making an excessive flex movement beyond a maximum flex movement amount, where the maximum flex movement amount is greatest among flex movement amounts necessary for the flex movement member 1 A or 1 B to drive the lens barrel 4 . This provides the driving apparatus with enough impact resistance, and prevents damage to the piezoelectric element.

1 . A driving apparatus for driving a driven body, comprising:
 a flex movement member for serving as a driving source to drive the driven body, the flex movement member including:
 a piezoelectric member which extends and contracts under electric control; and 
 a vibrational plate which is larger than the piezoelectric member, 
 the piezoelectric member and the vibrational plate being attached to each other; and 
   movement restricting means for restricting an excessive flex movement of the vibrational plate of the flex movement member, the movement restricting means being disposed at a position where the movement restricting means will not come into contact with the piezoelectric member of the flex movement member when the flex movement member is making an excessive flex movement beyond a maximum flex movement amount,   where the maximum flex movement amount is a greatest flex movement amount among flex movement amounts necessary for the flex movement member to drive the driven body.   
   
   
       2 . The driving apparatus according to  claim 1 , wherein:
 the movement restricting means restricts the excessive flex movement of the vibrational plate, the excessive flex movement being smaller than a tolerable flex movement amount of the flex movement member,   where the tolerable flex movement amount is a flex movement amount that the flex movement member is tolerable.   
   
   
       3 . The driving apparatus according to  claim 1 , further comprising:
 a support member which supports part of the flex movement member and includes a first protruding section as the movement restricting means, the first protruding section protruding toward the flex movement member.   
   
   
       4 . The driving apparatus according to  claim 3 , wherein the first protruding section is disposed to come into contact with part of the vibrational plate without coming into contact with the piezoelectric member, when the flex movement member is making the excessive flex movement. 
   
   
       5 . The driving apparatus according to  claim 3 , wherein the first protruding section is formed by an elastic material or a buffering material. 
   
   
       6 . The driving apparatus according to  claim 1 , wherein the vibrational plate includes a second protruding section as the movement restricting means. 
   
   
       7 . The driving apparatus according to  claim 6 , wherein the second protruding section has an elastic structure. 
   
   
       8 . The driving apparatus according to  claim 1 , comprising:
 first and second flex movement members serving as the flex movement members; and   a driving member, which
 (a) is connected with the first and second flex movement members, 
 (b) comes into contact with the driven body due to flex movement of the first and second flex movement members; and 
 (c) drives the driven body in a direction orthogonal to a flex movement direction of the flex movement members, 
   the movement restricting means respectively for each of the first and second flex movement members.